1. Field of the Invention
The present invention relates to a light pipe and an illuminating device having the light pipe, and more particularly, to a light pipe including an optical film having a plurality of prisms whose surface roughness falls within a predetermined range, and an illuminating device having the light pipe.
2. Description of the Related Art
Illuminating devices using a light pipe capable of transmitting light to a distant place with less transmission loss can be used in various places, for example, inside and outside a building. Light pipes, which are also referred to as light conduits, light guides or light tubes, have been used to effectively distribute light across a wide area for various purposes such as for illumination.
Light pipes can be used not only for illuminating certain points but also for illuminating whole areas. Light that transmits through a light pipe may be distributed to the outside of the light pipe for illuminating certain points or for maximizing the effect of illumination.
However, conventionally, it is difficult to appropriately control the transmission of light in a light pipe and the emission of light from a light pipe. Thus, it is difficult to achieve uniform brightness across a longitudinal direction of a light pipe.
Therefore, it is necessary to develop a light pipe which is easy to fabricate and is capable of transmitting and emitting light toward a distant place.